1. Field of the Invention
The present invention relates to a device for passively tracking individuals. More specifically, the present invention is directed to a device for recording the movement of individuals using GPS signals for later comparison with event data to determine if the individual was in the vicinity of the event within a given time frame.
2. Discussion of Background Information
Devices and methods for monitoring the movements of individuals are known. One example is a two-piece tracking unit that includes a tag attached to a limb of a wearer (e.g., on the wrist) tethered to a large suitcase or body-worn unit that carries batteries and associated circuitry. This device is an xe2x80x9cactivexe2x80x9d system in that it compares its position with certain ongoing restrictions to detect violations (e.g., a parolee enters a restricted area, such as a bar). The requirements of this type of active system dictate the large size and weight of this system. The associated manufacturing and operating costs have limited the commercial viability of these devices, such that it is believed that less than 1500 units are in actual use in the United States.
Smaller one-piece wearable units have been suggested, such as in U.S. Pat. No. 5,867,103 to Taylor and PCT/US00/16092 to Layson. Both disclose a self-contained device that can be worn around an individual""s limb. The devices include standard GPS receiving circuitry, a memory, a power source, and some methodology to download the contents of the memory to a remote station for comparison with other data, typically crime data.
A drawback of the Taylor device is that it fails to account for the power supply and management system necessary to make these devices commercially viable. Specifically, the power requirements of the Taylor device would only allow for short-term use based on available battery technology. Layson addresses this problem with various battery recharging schemes such as solar cells and high-speed inductive transfer. However, these procedures are not believed to be commercially viable. It is believed that efforts to solve these problems have focused on improved batteries and lower power consumption methodologies that would provide extensive use (on the order of thirty days) between recharges. To date, this approach has not proved successful.
A need therefore exists for a relatively small wearable tracking unit and associated methodology with a high commercial viability.
The above noted prior art devices produce location data that reflect a user""s location over time. This location data can be compared with incident data, such as crime data, to determine whether the user was in the area at the time of the incident. The noted Layson application contemplates that a database of several crime incidents can be compared with a database of movement of multiple users to identify instances of overlap. However, this type of comparison of raw databases would tax current computer limitations and be slow to produce results. Swifter analysis is preferable in these matters (if for no other reason than to minimize opportunity for criminal flight).
The present invention provides a device capable of monitoring the movement of a person.
According to an embodiment of the invention, a device for monitoring movement of an object is provided. A first module is configured to secure to the object. A second module, capable of electrically connecting to the first module, includes at least a rechargeable battery and a memory capable of storing a history of movement data. A third module, capable of electrically connecting with the second module, includes a data modem capable of connecting to a remote station, and a battery charger. When the second module is connected to the first module, the memory periodically records available location data representing a position of the device at the time of recording. When the second module is connected to the third module, the memory downloads through the data modem and the battery charger charges the battery.
Various options and features are preferably present in conjunction with the above embodiment. A band is capable of securing the first module to the object, the band being an electrically conductive plastic. The first module includes a coordinate receiver, and the battery powers the receiver when the first module is electrically connected to the second module. A fourth module is interchangeable with the second module. An initialization module capable of initializing the memory may be provided. The first and second modules, when connected, have a size and shape for easy support around the limb of a user.
According to another embodiment of the invention, a system for monitoring movement of an object is provided. A first module is configured to secure to the object, and includes a coordinate receiver and an antenna. A plurality of second modules are each capable of electrically connecting to the first module, and each include at least a rechargeable battery and a memory capable of storing a history of movement data from the coordinate receiver. A third module, capable of electrically connecting with at least one of the second modules, includes a data modem capable of connecting to a remote station, and a battery charger.
Various options and features are preferably present in conjunction with the above embodiment. By way of non-limiting example, when one of the second modules is connected to the first module, the memory periodically records available location data representing a position of the device at the time of recording, and when the one of the second modules is removed from the first module and connected to the third module, the memory downloads through the data modem and the battery charger charges the battery. Tamper detection circuitry in the first module is capable of logging a tamper event in the memory in response to attempted removal of the first module from the object.
According to yet another embodiment of the invention, a method for recording movement of an object, wherein a first module is attached to the object in a tamper resistant manner is provided. The method includes electrically connecting a second module to the first module, the second module including at least a memory and a battery, obtaining data representing a position of the first module at a particular time, storing the data on the memory in the second module, repeating the obtaining and storing for a period of time, after the period of time, disconnecting the second module from the first module and connecting the second module to a third module, the third module including at least a data modem and a battery charger, downloading the contents of the memory in the second module to a remote location through the data modem, and recharging the battery in the second module via the battery charger in the third module.
Various options and features are preferably present in conjunction with the above embodiment. By way of non-limiting example, at least one fourth module includes at least a memory and a battery. This embodiment preferably includes connecting the fourth module to the third module substantially when the second module is connected to the first module, and connecting the fourth module to the second module substantially when the second module is connected to the third module. The embodiment preferably includes storing tamper data in the memory in response to an attempt to remove the first module from the object.
According to still yet another embodiment of the invention, a method for recording movement of an object is provided. A first module is attached to the object in a tamper resistant manner, a plurality of second modules each include at least a memory and a battery, and a third module is configured to simultaneously connect with at least some of the plurality of second modules. The method of the embodiment includes connecting one of the plurality of second modules to the first module, connecting at least some of the plurality of second modules to the third module, obtaining, at the first module, data representing a position of the first module at a particular time, storing the data on the memory in the one of the plurality of second modules, repeating the obtaining and storing for a period of time, after the period of time, substituting the one of the plurality of second modules with one of the at least some of the plurality of second modules, such that the obtaining, storing, and repeating will continue with the one of the at least some of the plurality of second modules, connecting the one of the plurality of second modules to the third module, downloading the contents of the memory in the one of the plurality of second modules to a remote location through the data modem, and recharging the battery in the one of the plurality of second modules via the battery charger in the third module.